The instant invention broadly relates to the field of surgical instruments. More specifically, the invention relates to the field of hand held surgical instruments used for installing surgical implants. Still more specifically, the invention relates to a hand held wrench for installing surgical dental or orthopedic implants such as bolts or screws, into the boney tissues of a patient.
Surgical torque screwdriver devices are well known in the prior art. For instance, U.S. Pat. No. 4,852,386 to Grabovac, et al, teaches a hand-held torque tester for a hand-held torque-limiting tool that includes an elongated horizontal plate with a central longitudinal axis; top and bottom surfaces; front and rear ends and opposite sides; an elongated horizontal longitudinally-extending deflection beam with front and rear ends in spaced relationship above the top surface and parallel with the longitudinal axis of the plate; a vertical mounting pin depending from the front end of the beam and into the plate for free relative rotation therein and against vertical and horizontal displacement relative thereto; a driver part fixed to and projecting rearwardly from the rear end of the beam and having a central vertical drive opening to receive and establish rotary driving engagement with a part of a tool to be tested; a reaction assembly carried by the plate and defining laterally-spaced oppositely-disposed reaction surfaces at opposite sides of the beam adjacent to the rear end thereof; an elongate horizontal pointer with front and rear ends normally in spaced parallel relationship with the beam and having its rear end fixed to the driver and a front end portion projecting forwardly and toward the top surface of the plate forward of the beam; and, a force-indicating scale on and extending laterally of the plate below the front end of the pointer.
U.S. Pat. No. 5,226,906 to Crombie, et al, teaches an apparatus for installing a first part on a second part utilizing a threaded fastener passing through the first part and engaging the second part. The apparatus includes: a body; a drive assembly for applying torque to the threaded fastener. The drive assembly is rotatably mounted in the body and includes a socket assembly for receiving the threaded fastener; and an assembly for holding the first part adjacent to the body with the threaded fastener passing through the first part and received in the socket assembly. The holding assembly is configured and dimensioned to position the first part sufficiently close to the socket assembly so as to retain the threaded fastener therein. The drive assembly is rotatable with respect to the holding assembly. The first part may be installed on the second part without the necessity of a person touching or separately holding the first part after it is held by the holding assembly.
U.S. Pat. No. 5,352,231 to Brumfield, et al, teaches a nut starting tool assembly for driving a nut onto a threaded end of a bone bolt when the bolt is secured in animal bone. The tool assembly includes a shaft having a first end configured for fitting reception on a tool receiving end of a bone bolt, and an opposite second end configured for rotating the shaft. The shaft further incudes a storage assembly at an intermediate portion thereof for reception and temporary storage thereon of a nut to be installed on the threaded end of the bone bolt. The assembly further includes a sleeve coaxially disposed on the shaft and a first end configured for fitting reception on the nut when temporarily stored on the intermediate portion of the shaft; and an opposite second end configured to be manipulated independent of the shaft to move the nut off the storage assembly and drive the nut onto the threaded end of the bone bolt when the nut is received within the first end.
U.S. Pat. No. 5,368,480 to Balfour, et al, teaches a dental tightening torque limit tool holder that includes a tool fixture, a hub and a plurality of torque limit controls.
Universal wrenches which embody universal joints are well known in the prior art. For instance, U.S. Pat. No. 5,458,028 to Cleveland, teaches A universal joint device for interconnecting the handle portion and socket portion of a socket wrench is disclosed. The universal joint device is constructed with grooves for receiving the upper and lower ends of a coil spring which maintains the universal joint in alignment during both tension and compression. The universal joint device is also provided with recessed apertures for receiving washers or similar adjustment devices to allow the device to be customized for additional rigidity or flexibility. Previous universal joint devices are described, for example, in the following U.S. Pat. No. 1,102,863 to Bojas; U.S. Pat. No. 1,324,898 to Hopcraft; U.S. Pat. No. 2,327,821 to Rueb; U.S. Pat. No. 2,499,569 to Cooley; U.S. Pat. No. 3,122,901 to Thompson; U.S. Pat. No. 3,522,713 to Hayes; U.S. Pat. No. 4,065,941 to Aoki; U.S. Pat. No. 4,075,913 to Tye; and U.S. Pat. No. 4,721,493 to Lane; U.S. Pat. No. 4,108,027 to Lenker; U.S. Pat. No. 4,296,654 to Mercer.
The above disclosed prior art surgical implant wrenches: require complicated torque measurement assemblies that add to their cost of production; and/or, can be effectively operated only by a plurality of operators, thus requiring additional man power; and/or, require rotation of a handle about an implant to tighten it, thereby precluding their use in various confined environments.
Thus, despite the foregoing contributions of the prior art, it would nonetheless be desirable to provide the surgical practitioner with an improved surgical implant wrench, wherein the angle between the head and handle of the wrench can be selectively varied and thereafter selectively fixed so as to enable reduced costs of production, operation by single operators, and application to substantially any surgical environment regardless of available operating space requirements.